JP4869132B2 - How to repair or revamp a filter screen and a repaired or revamped filter screen - Google Patents

Abstract

A method of constructing a polymer support frame (10) over which woven wire cloth (158,159) is to be stretched and secured to form a sifting screen is described. The method comprises the steps of locating a reinforcing wire frame assembly in a mould tool. The wire frame comprises two parallel spaced apart arrays of reinforcing wires (48,50,54,56,60,62,64). After closing the mould, liquid polymer is injected into the mould tool so as to wholly encapsulate the wire frame and to form an article having an open central region criss-crossed by intersecting orthogonal ribs (14,16) bounded on all sides by a rigid flange. Each of the ribs (14,16) contains two of the parallel spaced apart wires of the frame assembly. After permitting the polymer to cure, the tool is opened and the article is removed. The wire frame assembly is located and held in shape and position by applying an inward force on opposite faces of the wire frame assembly within the mould tool, by fingers protruding inwardly from inside faces of the tool. The fingers engage the wire matrices when the tool closes. The polymer is typically a glass-reinforced plastics material, and in order to assist in bonding the wire cloth to the support frame (10) the faces of peripheral edge regions of the support frame (10) over which woven cloth (158,159) is laid and to which the cloth (158,159) is to be bonded by heating, are formed during moulding with a plurality of substantially parallel ridges (30,32).

Description

The present invention relates to a screen for use as a filter in a vibration filter device, such as a shaker, used to separate solids from oil liquid phase and mud collected by drilling operations in the oil drilling industry. In particular, the present invention relates to the construction and manufacture of support frames and the reuse of such frames.
The screen is formed by spreading and fixing a filter material such as cloth.

Background Examples of filter machines using screens as described above are given in GB 2237521 and GB 2229771.

One such screen is described in PCT / GB95 / 00411 (WO95 / 23655).
British Patent No. 2237521 British Patent No. 2229771 International Publication No. WO95 / 23655

  In previous screen designs, a woven sacrificial support mesh is provided below the upper woven mesh and the upper mesh is made of a wear material that is harder than at least the surface of the wire from which the lower mesh is knitted. Thus, the life of the screen is extended by making the degree of wear due to friction and vibration in use greater in the lower plow than in the upper plow. The specification also describes an improved design of the frame, where a woven plaid is pulled and bonded with an adhesive to form a sieving screen, which is made of glass-reinforced gas blown polypropylene. It has been proposed to provide long metal reinforced elements or rods formed from and embedded in glass reinforced polypropylene (GRP). The improved frame structure is shown in FIGS. 3 to 8 of the previous specification.

  It is an object of the present invention to provide an improved method of constructing an improved frame for use as a support for such a frame and a woven plaid layer, an improved screen formed from such a frame. As well as providing reusable frames in some situations.

SUMMARY OF THE INVENTION According to one aspect of the present invention, a method for constructing a polymer support frame underneath when a woven screen is spread and secured to form a sieving screen includes two parallel wires comprising reinforcing wires. Placing a wireframe assembly containing a spaced array into the mold tool, closing the tool, and injecting a liquid polymer to wrap the entire wireframe and surround all sides with rigid flanges Forming an article having an open central region intersected by intersecting orthogonal ribs, each rib including two parallel spaced wires of the wire frame assembly, and a polymer support frame The method for constructing further comprises the steps of curing the polymer, opening the device, and the molded article. The step of removing.

  By placing two side-by-side spaced wires extending through each rib, one extending near one end and the other extending near the opposite rib end, each The ribs have the rigidity of the beam, and the resulting frame has high rigidity and resistance to bending while remaining relatively light.

  Preferably, the wire frame is selected such that it provides sufficient structural rigidity to the support frame to prevent its deflection and that no change in tension in the gills will occur when installed.

  In addition, the wire frame is selected to provide sufficient strength to the support frame, and the support frame can withstand the shear stress that occurs when the frame is clamped to the vibration sieving machine.

  Typically, the wire frame is formed from a high tension straight steel wire, bent as needed, and in a preferred arrangement, the wire diameter is 2.5 mm.

The present invention also provides a method of making a reinforced wire frame for use in the above method for making a support frame, the method comprising:
Arranging the cut-length wires at equal intervals in the jig to form the first array;
Placing a second array of cut lengths of wires equidistant thereon, perpendicular to the first array;
Two arrays of wires are resistance welded at all intersections to form a matrix surrounded by a first straight line, two similar arrays of wires of similar cut length are similarly positioned in a jig, and orthogonal wires Forming a matrix surrounded by a second similar straight line by resistance welding the intersections of
The protruding length of the wire is bent with a press brake on at least two of the four sides of one side of the matrix surrounded by a straight line, and each protruding portion is first bent approximately upward and then at its end. Bending downward at a near point so that each protruding length of the end region extends in parallel with the plane containing the matrix but is offset therefrom;
And then resistance welding the staggered ends of the protruding wires of the one matrix to the protruding ends of the wires of the other matrix.

  Welding occurs in part through the middle of the transversely extending filler wire, the intersection is provided where a weld is formed between the parallel protruding ends of the reinforcing wire, and the filler wire protrudes in parallel. Facilitates resistance welding at the ends.

  Preferably, the wire frame structure is assembled such that each matrix faces and bends outward.

  During the molding process, the pressure in the mold apparatus can distort the framework, so that the outward bending of the opposing surface of the framework can change to a large inward bending, which causes the gaps in the molded frame to rise and fall. It has been found that long rod alignment in the end can be broken. To avoid this, it has been proposed to place at least one spacer in the framework so that the spacer prevents this collapse from occurring when the rod array tends to collapse inwardly. Yes.

  Preferably, a plurality of spacers are arranged in the wire frame structure, each spacer being attached to one or the other of the matrix and extending toward the other, the tendency for the matrix to collapse inward during molding This spacer resists when showing.

  In one embodiment, each spacer includes a length of wire bent into a shallow U shape, with its two ends bent outward to form two series lugs, which Can be welded to the underside of one of the wires forming one of the matrices, the top of the U portion being close to one of the wires of the other matrix, and the spacer between the two matrices in a given dimension And if this construction is subjected to a collapse force during molding, the top will engage the wire of the other matrix.

  The present invention also provides a method of forming a support frame around a wire frame structure as described above in a mold device as described above, wherein the inward force protrudes inwardly from the inner surface of the device. The finger applies an inward force to the opposing surface of the component within the mold tool, and the opposing matrix of the component engages from the outside when the mold is closed.

  In accordance with this method, the fingers sandwich the components in place and place them in parallel by the required inward movement of the two oppositely bent matrices, spaced apart by the desired distance.

  Typically, the fingers include inwardly projecting pegs that align with the wire intersections in the upper and lower reinforcement matrices, spacing the matrix from the corresponding upper and lower inner surfaces of the mold tool, It is embedded in the plastic material that is injected into the mold apparatus during the process.

Preferably, the end of the peg tapers towards the edge or point.
After the mold apparatus is opened and the protruding peg is removed from the post, an opening remains in the polymer. Thus, preferably, the method further comprises closing the opening with a plastic material or filler.

  Typically, the wireframe structure is supported in the mold by a retraction pin that protrudes through the mold wall to engage the structure and precisely position the structure in the mold.

The pins may be retracted when the mold is opened after the molding step is complete.
Conveniently, the pin is aligned with the protruding end of the wire making up the construct and is detachably joined to the end of the wire by a sleeve of plastic material, the opposite end being a pin and a reinforcing wire Receiving each end.

  Preferably, each sleeve passage is blocked to form two coaxial stop bores, each sleeve being embedded in the polymer during molding and when the engaging pin is retracted upon mold opening. The blocked passage remaining in the polymer serves to wrap the end of the end of the wire located at the inner end of the sleeve.

  Prior to molding, a peg made of a plastic material that is compatible with or the same polymer material that is injected into the mold and encases the wireframe component may be attached to the instrument, and this peg is integrated during molding. When the instrument is bonded and the instrument is released, the pegs will leave the instrument and remain in the frame.

  The protruding portion of each peg may be removed by grinding, filing, or cutting.

  The present invention thus provides a polymeric material support frame with reinforcing wires therein, and a woven plaid is bonded to the support frame to form a filter screen, the frame configured as described above. It is what is done.

  The present invention also provides a filter screen comprising a polymeric material support frame constructed as described above and provided with a reinforcing wire therein, with at least one woven plaid extending thereon and adhered to one surface thereof. .

  In general, it is desirable to tension the peg wire in the finished product, and for this purpose, the peg wire is tensioned while the plastic material is cooled and hardened and the woven peg is added to the frame. Adhere.

  This aspect of the present invention has the advantage that the adhesive in the step of applying the adhesive by heating the surface in contact with the scissors is useless, using a suitable polymer as the frame material.

  Of course, it is necessary to select a suitable plastic material to act as an adhesive medium for the woven plaid, and it has been found that polypropylene and polyethylene are suitable plastic materials, but the present invention relates to polypropylene and polyethylene. It is not limited to the use of.

  Regardless of whether polyethylene or polypropylene is used, it has been found that it is advantageous for either material to be blown with gas and reinforced with glass fibers.

  In a preferred arrangement, the mesh that is initially mounted on the support frame has a coarser mesh than the next layer of mesh that is mounted thereon.

  In particular, the present invention provides a filter screen in which two layers of woven plaid are attached and bonded together, the lower plow having a coarser mesh than the upper plow and forming the upper plow The tension of the wire is smaller than the tension of the wire forming the lower net.

  In accordance with another aspect of the present invention, a wire frame reinforcement structure for a support frame as described above is formed from a resistance welded steel wire matrix disposed in two parallel spaced apart surfaces, The matrix itself is welded along at least two edge regions by welding between the protruding ends of the two matrix wires.

  In accordance with another aspect of the present invention, in a method of forming a wire frame reinforced cage for incorporation in a mold apparatus for forming a polymeric material around to form a support frame for a filter screen, the cage is resistance welded The array of two similar straight lines of wire, and this method bends the wires protruding along at least two sides of one of the arrays to produce a bent portion of the wires of one array. Welding the ends to the protruding ends of the wires in the other array to maintain the separation of the two matrices.

  According to a further aspect of the present invention, a method of constructing a filter screen includes a plurality of similarly sized openings surrounded by straight lines defined by an integral straight lined matrix of wire reinforcement posts of polymer material. Forming a polymer support frame having an upper edge of each strut and an upper surface of each boundary portion of the support frame in a ridge, and a woven gill is attached and pulled over the ridge. At least by heating the ridges, the polymer material is sufficiently softened so that the net penetrates to its top, is embedded in it during cooling and is fixed in place, and after cooling, the tension in the wire of the net Is preserved.

The present invention also includes the step of causing different tensions in the two mesh wires after being bonded to the polymer support frame by differentially pulling the wires in one mesh with respect to the wires in the other mesh. It's okay.

  Preferably, the reinforced matrix is formed from a high strength steel wire with a nominal diameter of 2.5 mm, and a glass reinforced gas blown polypropylene polymer is injected into the mold tool under pressure and allowed to cure for a given period of time and molded. The first support frame was then removed and a nominal 30 mesh first woven peg formed from a stainless steel wire with a nominal diameter of 0.28 mm was attached and pulled over the support frame to provide a second woven plow. The net is mounted on the first net, and the second net is formed of a wire having a smaller diameter and a finer mesh size than the first net and is pulled in the same manner as the first net A force is applied on the surface of the support frame that supports the upper net, and heat is applied to soften the top of the ridge so that the two ridges are in the top of the ridge. So as to be written, after the heated force is cold is removed frame, wire cloth remains adhered to the highest portion of the ridge, in wire tension residual to form a 2 Tsunosuki network.

  One side of the support frame is bonded to the pavement by pushing the pegging wire into the softened material before the frame material is locally heated, cooled and hardened again. The reinforced wire frame produced as described above is formed from an embedded glass reinforced plastic material, preferably between the reinforced wire and the surface of the support frame member to which the woven plaid is bonded. The thickness of the plastic material is selected to be sufficient to allow the gill net to be embedded without contacting the reinforcing wire.

  Preferably, the plastic material may comprise polypropylene or polyethylene, gas blown and reinforced with glass fibers.

  According to a preferred feature of the present invention, in a support frame formed of a glass reinforced plastic material, the peripheral edge region surface of the support frame where the woven pavement is stacked and heated to bond the pegs is a plurality of closely spaced parallel arrays. When the surface is heated, the top of the ridge softens, and the woven gills that are tensioned over the top are softened by appropriate downward loading. It is possible to penetrate and be embedded in this top.

  In the method of constructing the filter screen using the support frame as described above, the top of the ridge facing the remaining portion of the support frame is preferably differentially heated by applying heat through a woven screen.

  In a generally rectangular support frame as described above, the ridges along each of the four side surfaces are parallel to the length dimension of each side surface, and the ridges at the four edge surfaces of the frame are woven meshes. In a direction perpendicular to the direction of pulling with respect to these edges.

  If the frame includes a matrix of wire reinforced struts that define a plurality of openings within the boundaries of the frame, sufficient plastic material is provided at each strut between the wire reinforcement therein and the peg mesh engaging surface. The strands of wire that form the pavement are embedded in the struts when the frame is heated and the appropriate force is applied to the frame, and different metals are used, even if the internal reinforcement wire and the peg are not in contact. The electrolytic action between the woven mesh and the reinforcing wire is prevented.

According to another preferred feature of the invention, the support frame as described above is made from a glass fiber reinforced plastic material, on which a plow is spread and bonded to form a sieving screen, The support frame includes a matrix of struts in a flange around the frame, in which the thickness of the strut engaging end of the strut is smaller than the thickness of the end of the farther strut region.

  Preferably, the cross section of the mesh engaging end of each strut is reduced, and the wire is embedded in the strut having the reduced cross section when the purse is heated.

  A post with a reduced cross section is preferably made by forming a ridge along its wire receiving edge.

  The present invention thus provides a support frame that is formed from a glass fiber reinforced plastic material and that spreads and adheres to the piling net to form a sieving screen, the support frame being an integral part of the interconnecting struts. Including an outer peripheral flange that surrounds the central area occupied by the stratified matrix, the flanges and struts are ridged, and the ridges that engage the plinth extend to different heights so that the topmost portions are side by side In different aspects.

  Preferably, the top of the ridge of the struts defining the integrated matrix is on the first surface, and the first surface is below the second surface including the top of the ridge of the surrounding flange.

  In the method of covering the support frame as described above, preferably heat is applied uniformly over the entire surface of the support frame by a flat heated platen, which pushes the sash into the top of the ridge and removes the plow. The net must be pushed into the top of the ridge of the surrounding flange before it can enter the top of the ridge of the struts forming an integrated matrix.

  In such a support frame, some or all of the outer ridges of the surrounding flange may extend higher than the ridges on the inner side of the flange, so that The top occupies a third surface above the second surface, and a greater amount of polymer adds heat to the mesh near the outer ends of the surrounding flanges than when close to the inner region of the flange. It melts and spreads when pressure is applied.

  By forming a ridge along the plinth mesh engaging edge, the area of the woven plaid that is actually obscured by being embedded in the plastic material is the minimum area required to support the plow. Reduced to In this way, the struts may have a lateral width that is significantly greater than the width of the top, but the area of the woven mesh that can be used to filter the liquid is the narrow width of the melted top. It will only decrease by the amount, not the entire area of the column. This occurs when the width of the mesh engaging surface of the support is the same as the width of the support itself.

  The struts are described as having a symmetric cross section that is ridged and generally has a topmost portion in the middle between the two parallel sides of the struts, and the upper end of the rectangular cross section of the rest of the struts. Can be considered to form an isosceles triangular network. However, this structure is merely a preferred form, and the triangular cross section of the upper region of the column is shifted so that the top of the ridge is displaced toward one side or the other side of the column when viewed from the end. If the triangle is a right triangle, the top is aligned with one or the other side of the rectangular section of the column, and the hypotenuse of the triangle is the other side of the top of the ridge and the rectangular column area. A slanted surface is formed between the edges.

Generally speaking, the main purpose of making the ridges ridges is to reduce the width of the plastic material that engages the woven mesh, so that it is just below the surface that is bonded to the mesh. It is possible to obtain an undulating effect simply by reducing the width of the column. This reduction in width can be achieved by defining the shoulder by a step (or by forming the shoulder by two steps on opposite sides), and the reduced area above the shoulder is associated with the plow. This results in a plastic surface with reduced width for mating. The difference between these arrangements and the triangular ridges is that in the former case, the lower side of the woven pruned mesh immediately adjacent to the left or right of the glued top is not completely obstructed until at least the shoulder, In the case of ridges, the slanted surface is used for filtering the liquid through a sash. In practice, however, a stronger triangular part is preferred because differential softening occurs to the height of the ridge, especially when heat is applied to the top.

  Preferably, the overall shape of the frame is rectangular and the flange extending along the two longer sides is wider than the flange along the two shorter sides, at least one of the shorter sides being It is adapted to be joined to the corresponding shorter side of a similar screen support frame made in the same way as the first.

  The present invention also provides a sieving screen which is composed of the support frame as described above, and in which the perforated net is spread and hermetically sealed.

  The present invention also relates to two screens configured as described above mounted on a support frame in a vibrating screen machine, where the short edge of the screen support frame forms a larger area for filtering. To be joined.

  The present invention also relates to a vibrating screen machine when two screens as described above are attached, one of the screens being mounted to be substantially horizontal in use and the other downstream of one screen. And is inclined upward in the direction in which the granular material moves through the machine.

  The present invention also relates to a support frame as described above, wherein one of the short side ends of the frame is adapted to engage and seal in combination with a corresponding edge of an adjacent similar support frame. When one frame slides toward each other, engagement and sealing occur by simply sliding one frame relative to the other frame.

  Sealing engagement of one frame with the other frame can occur when the two frames are in series or when the two frames are angled with respect to each other.

  There are a number of reasons for forming a screen as described above and mounting a large number of such screens in a vibrating screen machine with the edges in contact with the support framework to form a larger area for filtering. Is more advantageous.

  First, as already indicated, depending on the exciter design, a substantially horizontal first filtered area and a second area inclined upward in the direction of particle movement across the screen are required. And This is possible by forming the entire screen from two smaller screens, each screen constructed as described above, joined at the edges and need to change in slope. It can be taken.

  Second, each individual screen can be of a size and weight that can be easily handled by one person.

  Third, if one such screen is damaged, it is possible to easily remove it and insert a new one (sometimes without interfering with an undamaged screen). is there.

  In the support frame as described above, preferably, the cross section of each column is generally rectangular, the longer dimension is generally perpendicular to the plane of the frame, and the first reinforcing wire is bonded to the plow. Extending through each post near the edge, and a second side-by-side reinforcing wire extends through each post near the opposing edge, and these wires are bonded to the plastic material by a molding step, forming a beam with it To give this structure rigidity.

  Furthermore, in the support frame as described above, preferably the struts intersect with similar struts extending at right angles and are provided with a second assembly of reinforcing wires in parallel, which assembly is the second of the above assemblies. A pair of side-by-side spaced wires extend through each of the struts perpendicular to the first assembly of wires in a plane close to the plane including one.

  In such a support frame, each reinforcing wire aligned with the peripheral flange of the frame preferably extends to the flange at each end to increase the rigidity of the flange.

  Preferably, the end of the other wire of each pair is bent to align with the flange of the frame, the bent end extending to the flange near the end of the first said wire, and Further assist in strengthening the flange.

  Typically, the wire contacts at all intersecting points and is preferably welded at all such points.

Preferably, the ends of each pair of wires are welded at the portion occupying the flange.
In a wire frame assembly for a support frame as described above, cross-engagement between parallel wires at the flange is achieved by incorporating a fill or weld wire that extends intermediately between the ends of the wires. It may be introduced.

  Further reinforcement at the flange is provided by additional reinforcement wires extending in parallel in the direction of the length of the flange so that the additional reinforcement wires protrude above and below the protruding reinforcement wires entering the flange from the column. Welded to the end of the reinforced wire.

  The present invention provides a filter screen that includes a support frame as described above to which the mesh is bonded, and the mesh wire is taut and tensioned in the finished product. The tension is applied at least during the time when the frame material is cooled and hardened and the mesh is bonded to the frame.

  In accordance with another aspect of the present invention, there is provided a method for repairing or renewing a filter screen configured as described above, peeling a worn or damaged plaid from the surface of a polymer frame and placing a new plaid into the frame. And apply appropriate tension to apply heat to soften the surface of the frame where the mesh was spread, allowing the mesh to penetrate and embed in the softened plastic material, then cool the assembly Remove the pulling force and cut the edge of the plow to fit the flange surrounding the frame.

  In the repair or renovation method as described above, the plastic material is applied to the surface of the frame that receives the peg before attaching the peg to the surface of the frame, and further plastic material for bonding the peg to the frame. May be given.

  Insert the bare support frame into the mold and inject new polymer material into the mold to create a ridge on the surface of the frame similar to the ridge that was present when the frame was first manufactured. It may be molded again before giving.

  The present invention also provides a repaired or refurbished filter screen, where a worn or damaged plaid is replaced with a new plaid as described above.

  An apparatus for repairing or refurbishing a filter screen from which a worn screen has been peeled is advantageously a tray into which the exposed frame is inserted and a sheet placed on the top surface of the tray frame. Tensioning means in at least two different directions when the tensioning net is stretched over the frame, and tensioning means in the at least two different directions when the tensioning net is stretched over the frame Tension means for heating, means for heating the frame to soften the uppermost edge of the matrix of struts and the peripheral edge of the frame, and pushing the plow into the softened material and after cooling the peg is polymer frame And means for allowing it to remain glued to the edge of the frame.

  An apparatus as described above also makes it possible to fix at least a second peg on the first peg to adhere to the frame, preferably simultaneously with the first peg. Additional attachment means and tensioning means may be included.

  In such an apparatus, the amount of plastic material that can be used to bond the peg to the frame by applying the plastic material along each peg surface before or after the peg is stretched over the support frame. May be increased.

  The present invention also provides a method of repair or renovation, after removing a worn or damaged pruning net from a support frame, and then a plastic sheet similar in size and opening pattern to the support frame in plan view. Before or after the new mesh is overlaid and before heat and pressure are applied, provided in alignment over the frame to be repaired to provide additional plastic material to adhere the new mesh to the frame .

  Filter machines of the kind that can be fitted with a screen as described above are described in British Patent Specification Nos. 2237521 and 2299771, which are intended to be exemplary only, and Is not limited to the use of such screens in such machines.

The present invention will now be described by way of example with reference to the accompanying drawings.
Detailed Description of the Drawings FIG. 1 shows a frame to which a mesh of woven mesh woven in the manner described herein is stretched and bonded. This frame is generally indicated by 10 and includes a number of similarly sized rectangular openings, one of which is indicated by 12 and is formed by a matrix of orthogonal members surrounded by a straight line. One of the orthogonal members is indicated by 14 and the other is indicated by reference numeral 16.

On the two opposite sides, 18 and 20, the frame includes a relatively wide flange, whose upper surface is corrugated to form ridges and grooves 22. The other two edges 24, 26 and 28 are relatively narrow and contain only two or three ridges 30, 32. A woven plaid mesh (not shown) is spread over the ridged peripheral area of the frame by forming at least ridges from a plastic material that can be softened by heating and harden when cooled. Then, the peripheral edge of the frame can be heated and pushed into the ridge by pushing the mesh mesh into the softened top of the ridge. Allow the plastic material to cool and secure the mesh mesh in place, so that if the mesh is pulled in both directions before the heating step and the tension is maintained, then if the plastic material cools down, The tension will remain in the unfolded plaid net layer. If the pulling net is differentially pulled so that it is normally preferred so that the tension on one is greater than the tension on the other, the difference will appear in the residual tension held in the pulling net.

  A similar ridge is formed along the top of each orthogonal cross member, and the ridge of the cross member is sunk after heating over the entire surface area of the frame embeds the screen into the ridges of the surrounding flanges. By positioning the mesh to engage the mesh, the mesh of the woven mesh is secured to the top of the cross member, and the cross member securely secures the woven mesh in place when the assembly cools for further support. Bring.

  In a typical example, the mesh size of the first mesh is approximately 30 and the mesh size of the second mesh is in the range of 100-300. Each consists of a heat-treated stainless steel wire that constitutes a first grate, typically on the order of 0.28 mm in diameter.

  In accordance with a preferred aspect of the present invention, the frame is formed from a plastic material or similar reinforcing material that can be reinforced with glass fibers, and the edge regions and cross members of the frame are all welded in the manner described below to form a wire frame reinforced structure. It is reinforced with a long steel wire that forms. Typically, the steel wire has a diameter of 2.5 mm and is used to construct a reinforced wire frame.

  A frame, such as that shown in FIG. 1, typically inserts a reinforced framework into a suitable mold tool and applies pressure to inject the plastic material into the tool so that the wire reinforced frame (typically made of glass fiber) is used. Formed by being completely confined within the (reinforced) plastic material and ensuring that the reinforced wire is completely encased in the plastic material when released from the mold.

  In FIG. 2, the cross-sectional view at CC shows a cross section of the cross member 14, and it can be seen that the cross members 16 that are orthogonal to each other extend on both sides of 14. Edge regions 18 and 20 are reinforced by frame members 34 and 36.

  A cross section at BB in FIG. 1 is shown in FIG. Cross member 14 is still visible, but now it can be seen that an orthogonal cross member 38 intersects 14 and the opening that BB crosses is shown at 40.

  A ridge like 24 is visible on the upper surface of the flange 20 with a relatively wide edge, and the inside of the two ridges along the narrow edge 28, also identified in FIG. The ridges 42 can also be distinguished. The ridged end 28 is cut off at opposite ends 44 and 46 as shown in FIG.

  FIG. 3 also shows some of the metal reinforcing rods that form the reinforcing framework. Two rods, designated 48 and 50, extend through the upper and lower regions of the cross member 38, respectively.

  A similar pair of rods extends through the upper and lower regions of each of the parallel cross members, such as 16.

  Extending through each of the orthogonally extending cross members shown at 14 and 52, respectively, are two similar pairs of rods shown at 54 and 56 and 58 and 60, respectively. At the intersections between the rods, the rods are welded by electrical resistance welding or the like.

  Additional reinforcing rods 62 and 64 extend in parallel with rods 54 and 58 through edge region 20 and are resistance welded to extended ends such as rod 48 where they extend into flange 20.

  The extension of the lower rod, such as 50, is bent upwardly as shown at 66 and is coextensive with or in contact with the lower side of the upper pair of rods, eg, the extension of the rod 48. And is resistance-welded to it. In this way, the upper layers of cross welded rods, such as 48, 54, 58, 62 and 64, are secured to the lower rod layers, such as 50, 56, 60, to form a single reinforced structure. To do.

  FIG. 4 is an enlarged view of a part of the cross section taken along the line AA, compared to FIG.

  FIG. 4 also shows the details of the snap-in locking arrangement at the opposite ends of the frame. That is, the protrusion 68 extending at the left end is separated from the left end face 70 and extends across the entire width of the frame, while the end face 72 is cut off at the other end of the frame to define a rebate 74 and adjacent The projection 68 of the frame is received.

  The end surface 72 also includes an upstanding portion 76 that cooperates with opposing end regions of the end surface 70 of the adjacent frame to separate the two end surfaces by the thickness of the upstanding portion 76. This also helps to properly secure the rebate 78 of the protrusion 68 under the lip 80 along the upper end of the rebate 74.

  FIG. 4 also shows a small opening that can be left above the point where the reinforcing grid intersects when an isolated pit or stool is used in the mold instrument to position the reinforcing grid in the instrument. Two of them are shown at 82 and 84.

  FIG. 5 is a partial end view from the direction of arrow D in FIG. 1, showing an upright portion 76 and an end surface 72 at the right end of the frame as shown in FIG. Similarly, a lip 80 is shown with a lower notch 86 in the shoulder created by the rebate 74.

  FIG. 6 shows a method of joining two frames 10 and 10 ', each similar to that shown in FIG. 1, and two edges 26' and 28 will be described in more detail below with reference to the following figures. Are in contact / engaged.

  In use, the wider flanges 18 and 20, 18 'and 20', and one end flange 28 'are mated in an appropriate manner within the basket of the shaker assembly. In order to allow the solid material to travel beyond the edge without being disturbed during vibration, in practice it is only necessary to support the end flange 20 below it.

  Inflatable interlocking seals may be used along edges 20, 20 ', 28', 18 'and 18.

  As shown in FIG. 7, the two frames 10 and 10 'may be aligned, and depending on the exciter, the aligned frames are advantageously mounted to be inclined with respect to the horizontal direction and filtered. An upward slope that climbs as the mud should move by vibration is provided. Typically, this oscillating motion has a component in the direction of the approximate alignment of the two frames and a direction perpendicular thereto.

The two separate parts forming the joint are shown enlarged in FIGS. 8 and 9,
Details of this engagement are shown in FIG. FIG. 9 shows an edge 28 that includes a protruding portion, generally designated 68, that extends across the width of the frame and fits under the shoulder 80 of the rebate 74 of the cooperating frame 10. .

  Upright 76 may include a separate member in the form of a seal that may be made of a plastic material or rubber or a composite thereof. Instead, as shown, it may only include protruding ridges made during molding, made of the material that makes up the rest of the frame.

  When two frames are mounted on the shaker, the frame 10 'is first introduced into the shaker basket and then the frame 10 is introduced. When the right end of the frame 10 (as viewed in FIG. 6) is lifted so that an angle is created between the frame 10 and the surface of the frame 10 ′, the protrusion 68 is moved under the shoulder 80 by the rebate 74. As a result, the ridge 88 of the protrusion 68 engages the notch 86 on the rear side of the shoulder 80. Once 88 has entered 86, the frame 10 can be lowered and aligned with 10 ', and if the dimensions are carefully selected, the sloped surface 90 will engage the sloped lower side 92 and upright only under those conditions. The part 76 'contacts the surface 70 at the other frame end. This is shown more clearly in FIG.

  By defining the dimensions in this way, when the two frames are pushed together, the fluid captured between the ends of the frames is squeezed through the remaining gap between the surfaces, and the lowest gap shown in FIG. Allow drainage through.

  Depending on the exciter, two screens as shown in FIG. 6 (each consisting of a spread of woven mesh on top of the frame) can be tilted relative to each other instead of being aligned as shown in FIG. It is preferable to provide it. To this end, an alternative edge structure may be incorporated by providing a small step between the two top surfaces so that one frame end can be attached to the other.

FIG. 11 is a plan view of such a frame.
12, 13 and 14 are end faces and cross-sectional views of the frame shown in FIG. 11, which is enlarged in the case of FIG.

  Essentially, the structure of the central region of the frame is similar to the structure of the frame of FIG. Thus, the mesh is secured to the upper edges of orthogonal cross members such as outer flanges 100, 102, 104 and 106 and 108, 110, 112, and the like.

  Relatively wide flanges 100 and 102 are shown with cross members 110 and 112 in FIGS.

  Each cross member is ridged along its upper edge as best seen from the hidden details of items 110 and 112 in FIG. Note that the ridges are indicated by reference numerals 114 and 116, and the highest point of the ridges 114 and 116 is below the highest point of the ridge 118 along the edge 106 (see FIG. 11). In this way, when the GRP material is heated to accept the mesh of the mesh, the heating of the mesh and the welding to the regions 100 to 106 outside the frame is a central region comprising cross members 108, 110, etc. Will surely happen before the top.

The ends 104 and 106 are designed to be engageable with each other, so the end 106 is formed with a pair of grips 120 and 122 that extend across the full width of the frame ends and face each other. An end 104 of a second frame (not shown) can be received. This opposite end includes a flange 124 extending with three ridges 126 formed on the top surface, and the height of the flange along with the thickness of the flange 124 is between the upper and lower jaws 120 and 122. Since it is equal to the inner spacing, the end 124 can be pushed into the long slot formed by the pair of grippers 120 and 122.

  At 128, the lower portion of the upper gripping tool faces upwards away from the lower gripping tool so that the end portion 124 can be easily inserted. Since the ridge 126 is made of a plastic-based material, it can be deformed, and by accurately sizing the gap between the grips 120 and 122, the flange 104 can be pressed firmly into the gaps of these grips. The ridges 126 form a partial seal between the flange 124 and the lower side 128 of the grip 120 on the upper side of the end flange 106.

  Similar to the frame shown in FIGS. 1-10, the frame of FIG. 11 includes a grid of reinforcing rods, which are welded or joined at the intersections of the grids and are generally shown at 130 and 132 with reference to FIG. It is comprised from the upper and lower layers shown. The end of the lower layer of the rod is bent upward and welded to the aligned rod of the upper layer of end flange 104 as shown at 134 in FIG.

  As can be seen from the partial cross-sectional view of FIG. 15, the upper and lower layers of the rod terminate at the other end of the frame without converging to one point.

  The two edges 100 and 102 are reinforced in the same manner as the end flange 104, and the end of the lower layer rod 136 is bent upwardly to join the upper rod 140 as shown at 138 in FIG. Welded or otherwise joined to the upper rod 140.

  All rods are generally contained within a linear array of intersecting members excluding the flange ends of the frame.

  The partial cross-sectional view of FIG. 17 is taken along line CC of FIG. 11, and cross members 110 and 112 are shown in both drawings.

  FIG. 18 shows a method of attaching two frames as shown in FIGS. 11 to 17 so that one makes a shallow angle with respect to the other. One frame is shown at 14.

  FIG. 18A shows a variation of the interengagement that can be done in the same way that an end such as 126 engages in a long “socket” between grips such as 120 and 122, but in this case both ends. The part is “female” (ie equivalent to the end 106) and one upper flange can be pushed into the other socket, thus maintaining a good seal. Similar reference numbers are used to refer to items common to FIG. 18A and the preceding and subsequent drawings.

  Also shown in FIG. 17 are plastic support inserts or stools, such as those shown at 142 and 144, which are placed within the mold apparatus to engage the gaps in the crossing rods. When the frame is closed, the frame interval is correctly provided in the mold apparatus.

  In an alternative spacing arrangement, the fingers can be spaced or positioned by fingers protruding from the inner surface of the mold tool, and the molded part can be formed by opening the tool in the plastic molding. After removal, it may be filled with a suitable material, or it may be filled with a plastic material that will form the struts when heat and pressure are applied to the frame during the manufacturing process.

  The preferred arrangement uses an isolated support or stool because it can be used not only to center the reinforcing framework in the mold apparatus, but also to tilt the framework slightly up and down If so, the spacing between the array of upper and lower rods can be correctly redefined when the mold tool is closed. The preferred shape of such an isolated support is illustrated in FIGS. 19 to 23 and will be described with reference to these drawings.

  In order to prevent the molding pressure in the instrument from pushing the array surrounded by the upper and lower walls of the rod / wire to reduce its spacing, spacer 143 (typically a bent wire, of which Is provided as shown in FIG. 17C, which is shaped in one or the other of the above and allowed to move relative to each other beyond the critical dimension defined by the spacer.

  In the same way, a plastic ferrule as shown in FIG. 17 and shown at 146 can be inserted into the mold apparatus to cover the end of the rod that may otherwise remain exposed.

  In a preferred mold device, the welded reinforcement framework is part of the device at one end of the rod (140) forming the framework at one end and one of the retractable pins at the other end. With attached double-ended plastic ferrules (146), two can be supported by four retractable pins (145) on opposite sides of the framework. After molding, the pin (145) is retracted from the retaining hole of the ferrule (146) that is embedded in the GRP during molding to allow the molded article to be removed from the instrument.

An example is shown in FIGS. 17A and 17B.
If the support insert or ferrule protrudes after molding, it can be removed by cutting or filing.

  As described above in connection with FIG. 11 and the like, the ridge vertex of the edge flange of the frame shown in FIGS. 1 to 10 is different from the ridge vertex of the cross member ridges such as 14 and 16. Alternatively, in a preferred arrangement, one or more of the outer ridges along the flanges such as 18, 20, 26 and 28 extend above the plane containing the apexes of the cross members such as 14 and 16. In this way, the peripheral region of the frame has a greater amount of plastic material that is heated and softened before the woven plaid mesh is placed therein as compared to the plastic material along the cross member. Therefore, the perimeter region must be bonded before the pruned net contacts and is bonded to the apexes of the cross members 14 and 16 and the like.

  Figures 19 to 23 show a preferred isolated support location for the reinforcing rod, generally and enlarged in view of scale. Here, each support includes a metal pin 148 at the end of the chisel that tapers as shown in FIG. The chisel end 150 is most clearly shown in FIG.

  As shown in FIG. 23, the pins are positioned such that each chisel end 150 extends generally perpendicular to the length dimension of the rod 48 that engages within the mold tool.

Thanks to the chisel end 150 and the taper 152, the liquid plastic material tapered similarly as 154 at the apex of the frame cross member when the instrument was opened and the chisel end was pulled out of the mold. Flow around the taper and chisel edge so that the recess remains. Each recess left by the pin 148 thus only exposes a small area 156 of the wire (see FIG. 20).

  When the woven pavement is spread over the top of the frame and the peg and frame are heated, the plastic material flows into the lower end of each recess left by the chisel end, such as 150. In this way, a barrier is provided between the mesh of the mesh that is filled with a small area and a reinforcing rod such as 48 (see FIG. 3).

FIG. 24 is a perspective view of the female end of the frame 10 ′ of FIG.
A sealing ridge 76 is visible above the groove 74, into which a long male “projection” 68 (see FIG. 9) is fitted.

  A woven plaid is spread over the frame, the upper one of which is shown in part 158 and the lower one is shown in part 159. Two such pavement nets, which are one above the other, are spread over the frame, the mesh of the lower plow net is coarser than the mesh of the upper plow net, and the tension of the lower plow is higher Greater than the net tension.

  By heating at least the top surface of the frame and applying a uniform downward pressure on the mesh, the top of the plastic frame softens and the mesh sinks into the top, which also becomes flat in the process. It will be. Upon cooling, the plastic material hardens and secures the plaid in place.

  The top of the outermost ridge 160 of the flange extends upward above the top of the inner ridge of the same flange.

  The flat part between the grooves at the junction between the two screens as shown in FIGS. 7 and 18 does not prevent the granular material from progressing from one screen to the next. It needs to be as small as possible.

  Similarly, the front edge of the screen where the solid crosses over the edge, for example across the skip, needs to be as small as possible.

  Due to the joint provided by the ends attached to each other as shown in FIGS. 18 and 18A, the edge 120 of the upper frame is over the plaid mesh of the lower frame. In this manner, the ineffective area that is not screened is reduced to the minimum, ie, the ridge-shaped end portion 120.

  The joint resulting from the engagement as shown in FIGS. 18 and 18A also seals the joint, prevents liquid leakage, and jumps across the joint between one frame and the other. It has been found to reduce the risk. This appears to be possible because the structural member is formed by a reinforced wire, and when the reinforced wire is pulled, such as when the frame is pushed from above and below in a mold tool, the frame and plastic material are resistant to bending. Therefore, the tendency to jump up is minimized.

The screen is preferably glued to the top using flash heating.
Conveniently, a welding wire is used between parallel rods over 48, 66 (see FIG. 3), etc., as indicated by reference numeral 49.

  Reference is made to the drawings and associated description of British patent specifications 2237521 and 2299771 to illustrate a type of filter machine that may be equipped with a screen as described herein.

FIG. 2 is a plan view of a frame for use as a filter in a vibration filter apparatus such as a vibrator for separating a solid from a petroleum liquid phase and muddy water by fixing a plow net over the frame and fixing it. Form a screen. It is sectional drawing in CC of FIG. It is a fragmentary sectional view in BB of FIG. It is a fragmentary sectional view in AA of FIG. It is the fragmentary end elevation in D of the flame | frame of FIG. 1, and has expanded and shown. It is the fragmentary sectional view cut in the direction of arrow D of FIG. 1, and has expanded and shown. FIG. 2 is a reduced plan view showing two screens, and each of the two screens uses a frame as shown in FIG. 1 and is configured to form a larger screen area in contact with the aligned edges. It is a side view of the direction of the arrow VII of FIG. 8 is an enlarged view of two internal engagement edge regions of the two frames of FIGS. 6 and 7. FIG. 8 is an enlarged view of two internal engagement edge regions of the two frames of FIGS. 6 and 7. FIG. It is an expanded sectional view of the area | region where the two flame | frames shown enclosed with the circle | round | yen by VIII of FIG. FIG. 2 is a plan view of another frame similar to the frame of FIG. 1 such that when the frame joins another similar frame, the two frames form an angle with each other when viewed from the side. The edges are in contact with each other. FIG. 12 is an end view at “B” in FIG. 11. It is sectional drawing in DD of FIG. FIG. 12 is a partial end view (enlarged view) at “B” in FIG. 11. It is a fragmentary sectional view in AA of the edge part of the left side of the flame | frame shown in FIG. FIG. 12 is a partial cross-sectional view at AA of the right end of the frame of FIG. 11 showing the wire reinforcement structure in more detail and an insert is required to support it in the mold tool. 12 is a (enlarged) partial cross-sectional view of the frame of FIG. 11 at CC. FIG. A method of supporting a wire frame in a molding tool by a ferrule that is integrated with a molded frame and covers an end of the wire will be described. A method of supporting a wire frame in a molding tool by a ferrule that is integrated with a molded frame and covers an end of the wire is shown. Fig. 5 shows a bent wire spacer to prevent the wire frame from collapsing in the mold tool when the polymer is injected under pressure. FIG. 12 is a side view of two frames of the type shown in FIG. 11 with the edges in contact and engaging. It is an enlarged view of a junction part. It is a side view of the cross section of a part of cross | intersection part between the matrix support members of a flame | frame as shown in FIG. FIG. 20 is a plan view of the frame portion shown in FIG. 19. FIG. 21 is an elevational view of a support for placing wire reinforcement structures at intersections as shown in FIGS. 19 and 20. FIG. 22 is an enlarged end view of the lower end of the support of FIG. 21. FIG. 5 is an enlarged view of a preferred engagement of the chisel end of an independent support with a reinforcing rod. A portion of the completed screen is shown.

Claims (5)

A method of repairing or renewing a filter screen comprising a support frame in which ridges are formed in parallel to a surrounding surface, and a sash is embedded in the ridge,
(A) peeling the worn or damaged plaid from the surface of the frame;
(B) providing a new plaid on the frame to apply appropriate tension;
(C) heat is applied, the frame in which the new wire cloth is stretched over, softening the ridged surface, the wire cloth is therein to penetrate the softened plastic material of said surface Steps to be able to be buried,
(D) cooling the frame and a new plow associated therewith;
(E) removing the applied tension;
(F) cutting the exposed edge of the plow mesh to a surrounding surface.   A plastic material is provided on a surface of the frame that receives the peg before attaching the peg on the frame, providing additional plastic material for adhering the peg to the frame. The method described in 1.   Prior to step (b), the frame was first manufactured on the surface of the frame by inserting the support frame from which the mesh was peeled off into the mold and injecting new polymer material into the mold. 3. A method according to claim 1 or 2, wherein a ridge similar to that sometimes occurred is reformed.   After removing the worn or damaged sash from the support frame, place a new sash on the frame to be repaired with a plastic sheet similar in size and pattern to the support frame and openings when viewed in plan. 2. Before or after overhanging and before applying heat and pressure, align and place to provide additional plastic material to bond the new plow to the frame. Or the method of 3. 5. A repaired or renewed filter screen manufactured by the method according to claim 1, wherein the screen has a support frame, and ridges are juxtaposed on the peripheral surface of the support frame. A worn or damaged plaid is peeled off from the frame and a new plaid is placed over the frame and stretched over the surface by heat. Rarely repaired or renewed filter screens where the exposed edges of the plow are trimmed to the surrounding surface.

Images